Method of forming wire filling for regenerators



Feb. 26, 1952 F. L. VAN WEENEN ET AL 2,587,252

METHOD OF FORMING WIRE FILLING FOR REGENERATORS Filed Aug. 29, 1945 1 add.

Patented Feb. 26, 1952 UNITED STATES ENT OF F ICE METHOD OFF ORMING WIRE FILLING FOR- REGENERATORS Conm, as'tru'stee Application August29, 1945, Serial.No.=613,397

In the Netherlands September 2,,1941

Section-1', Public llaw 690; August 81946 Patent expires September 2, 1961 2. Claims.. (Cl. 29-15373).

This invention relates to an improvement ina regenerator construction and: to" a method of forming an interior core for such improved construction; and more particularly to a filling or mass for the regenerator of a hot-gas motor;

It has already been proposed to use a regenerator in a hot-air motor. This'regenerator contains afilling or mass consisting of filamentary material which is'realised in the form of wire cloth. Such regenerators, which are provided between thehot part and the cold part of the motor have for its purpose to cool as much as possible the medium flowing from the hot side. to the cold side of the motor and to return again the ab,-

sorbed heat to the medium when flowing in the opposite direction. By the use of a good-regenerator-the efliciency of such amotor is increased.

The present invention. relates to. an improved type of regener-atorwhi'ch lends itself moreparticularly for use in a hot-gas motor. Theexpression hot-gas motor is to be understood to mean a motor having a hot part and a cold: part which parts communicate with each other. In these motors the working medium is alternately in the hot part and in the cold part in such manner that the expanding heated medium is enabled to act upon a piston. One example of a hot-gas motor is the hot-air motor above referred to, in which the working medium consists of air. Sometimes hot-gas motors are realised as turbines. In such a motor the condition may be imagined that always the same. air partakes in the cycle, in which case the motor. isv said to have a closed cycle. However, it is also possible that the medium is periodically replaced entirely or artly, for instance after each stroke, by the same medium but having, for instance, a different temperature, in which case the motor is said to have.

an open circuit.

The regenerator according to the invention exhibits the feature that the filling or mass thereof consists of One or more composite elements each of which consists of. a. certain number of wires, the wires in each element jointly exhibiting a pattern most beneficial to the function assigned the regenerator.

In the well-known regenerators, in Which the regenerator chamber is filled with filamentary material, these wires are usually liberally located in the regenerator chamber. In these well-known regenerators one usually proceeds in such manner that a definite quantity of filamentary material is introduced into the regenerator chamber, no attention being paid to the position of the regenerator filamentary material in the chamber.

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2; Due to this the massxof wire is; not evenly distributed throughout the regenerator chamber, so that the filling mass may exhibit comparatively broad channels at one. point and strong concentrations of wire materialat another point, which is harmful to the operation of the regenerator.

In the case just referred to the larger part of the medium circulating through. the. regenerator will pass through the comparatively broad. channels, whereas those parts of. the. filling or mass exhibiting strong concentrationsoi'wire are. practical-ly inoperative.

A primary object of this-inventionis: to provide an improved regenerator construction and a method of forming the same.

A further importantobject of this invention is to provide an efficientregenerator filling forhotgas apparatus anda method: offorming said-fillmg.

Another object. of this; invention. is to providev a method'of forming a: novelfilling for a regenerator.

Further objects, features and advantages of this invention will beapparent as the description proceeds hereinafter;

In the drawing 1.

Fig. 1 is a developed. or exploded view of a mandrel or' coil formed thereon showing a schematic plan for winding a wire coil for a regenerator thereon with a honeycomb pattern, A-A representing the axis of the coil.

Fig. 2 is a perspective view of the coil wound according to the Fig. 1 schematic.

Fig. 3 is a developed view ofthe completed coil showing suggested sectors of coil material.

Fig. 4 is a perspective view of an embodiment of a regenerator core produced according to the invention; and

Fig. 5 is another embodiment of a regenerator core produced according to the invention.

These drawbacks are obviated in the regenerator according to the invention, since therein the wires in each element are located according to a definite pattern so that one may be sure that the mass of wire is distributed as evenly as possible throughout the regenerator chamber.

It has been found advisable to choose a honeycomb coil pattern for the coil pattern of the wires in each element. The thickness of the wires in each coil preferably amounts to 0.5 mm. at the most.

Furthermore the regenerator according to the invention is advantageous on account of the fact that, when realising the elements of the filling or mass in the manner referred to above, they can be made in a very simple manner. According to the invention we preferably proceed as follows in making this filling mass. A wire is wound on a mandrel into the form of a coil preferably having a honeycomb pattern, which coil may have a fairly large axial dimension and a comparatively small thickness relatively to the diameter of the coil. After the coil has been wound on the mandrel it is impregnated with some suitable soluble binder such as wax or parafiin for maintaining the wires in the correct position with respect to one another, followed by developing it in a fiat plane e. g. by cutting it according to a generatrix. From this developed coil the elements to be used for building up the filling mass may be out. After that these elements are built up in the regenerator chamber to form a filling mass having the desired shape, whereupon the binder is removed. When the regenerator chamber is cylindrical, round discs are cut from the developed coil which may be piled together in the regenerator chamber. If, in contradistinction thereto, the regenerator chamber has an annular cross-section for instance, preferably ring-sector shaped plates are cut from the developed coil which are subsequently piled together in the chamber. The removal of the binder which may consist of wax or paraifin may be effected, for instance, by passing a suitable solvent through the regenerator. As an alternative a fiat coil having a fairly large thickness may be wound from the wire and this coil may be used as a filling mass either as a whole, for instance in an annular regenerator, or in pieces.

Supposing D to be the outer diameter of the coil shown in Fig. 2, 1r D represents the circumference of this coil. Fig. 1 shows how the wire which, inthe present case, has a thickness of 0.03 mm. and consists of chromium nickel, is wound on the coil. The wire is wound. on the coil in the sequence of the figures indicated in this figure. From the figure it follows that this winding method yields a coil having the honeycomb pattern. Thus various or several apertures B arise between the wires. For the sake of clearness the size of these apertures has been materially exaggerated relatively to the diameter of the used Wire. As a rule the dimension between two neighbouring windings amounts to about 3 to 5 times the diameter of the used wire. Fig. 2 illustrates how to obtain the exploded view shown in Fig. 1. After winding the coil shown in Fig. 2 from the wire material, it is impregnated with a binder such as wax or paraffin and subsequently cut and developed according to the plane V. In this way the exploded view is obtained as in Figure 1 and erator. The said pieces are juxtaposed and su perposed similarly to the stones of a chimney in such manner that the vertical joints between the pieces of one layer do not lie above the joints between the pieces of the next layer. After piling the pieces in the regenerator chamber and after compressing them the impregnating medium is removed from the pieces by means of a suitable solvent such as carbon tetrachloride.

Fig. 5 represents another example of forming .a coil-shaped member which lends itself for use as a whole or subdivided as a filling mass in the regenerator chamber. In this case the wire is wound on pins in such manner that a circular central hole is left in the coil. After the coil has been wound it is impregnated again with a binder, located in the regenerator chamber after having been subdivided or not and compressed the binder finally being removed by means of a solvent,

What We claim is:

1. A method of forming a wire filling for a regenerator comprising the steps of winding .a wire of small diameter on a mandrel according to a honeycomb pattern, impregnating the resultant coil with a soluble binder, cutting said coil along a line parallel to the longitudinal axis of said mandrel, developing said coil into a plane surface, cutting. ring sectors out of said developed coil, stacking said sectors in an overlapping manner in any suitable regener-ator container, and dissolving said binder from said various ring sectors.

2. A method of forming a filling for a regenerator comprising the steps of winding a fine wire on a mandrel according to a pattern having substantiailly equal parallelogram openings, the dimension between two neighboring windings amounting to about three to five times the diameter of the wire, of impregnating the resultant coil with a suitable soluble binder, cutting said coil in one piece from said mandrel, cutting pieces from said out coil, stacking said coil pieces in a suitable container for a regenerator, and washing away said binder from said coil pieces.

FRANCISCUS LAMBERTUS VAN WEENEN. HEINRICH DE BREY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 15,771 McDonough Sept. 23, 1856 30,306 Ericsson Oct. 9, 1860 30,700 Wilcox, Jr. Nov. 20, 1860 206,597 McKinley July 30, 1878 939,839 I-Iimes Nov. 9, 1909 1,694,939 Heftler Dec. 11, 1928 1,745,426 Kraemer et a1. Feb. 4, 1930 2,245,840 Webb June 17, 1941 2,276,572 Gunn Mar. 17, 1942 2,334,263 Hartwell Nov. 16, 1943 2,354,395 Mason July 25, 1944 

